Login | Register

Oxidation Studies of Nickel, Copper and Cobalt Complexes of Classic Ligands Made Redox-Active

Title:

Oxidation Studies of Nickel, Copper and Cobalt Complexes of Classic Ligands Made Redox-Active

de Bellefeuille, David (2014) Oxidation Studies of Nickel, Copper and Cobalt Complexes of Classic Ligands Made Redox-Active. Masters thesis, Concordia University.

[thumbnail of David_de_Bellefeuille-Thesis.pdf]
Preview
Text (application/pdf)
David_de_Bellefeuille-Thesis.pdf - Accepted Version
Available under License Spectrum Terms of Access.
11MB

Abstract

In several oxidoreductase metalloenzymes, organic cofactors are transiently converted to radicals in order to achieve efficient catalytic turnover. This is, for example, the case of a tyrosine residue in galactose oxidase. Similarly, small-molecule catalysis can be improved when a transient radical ligand is involved. The present work aims at tailoring the structure of three classic ligands to make them redox-active, i.e. active participants in the electronic structure and reactivity of their complexes upon oxidation. The approach is
to render an aromatic moiety on the ligand electron-rich by addition of NMe2 substituents.
The first chapter describes
a neutral Ni(II) complex
with 1. This complex
undergoes two reversible
oxidations that were
characterized by electrochemistry, electron paramagnetic resonance spectroscopy, optical spectroscopy and density functional theory. These oxidations are ligand-based, producing a radical ligand and a diiminoquinone successively.
The second chapter investigates Cu(II) complexes of 1 and 2, for the bio-relevance of Cu in several oxidoreductases. Both ligands oxidize to a radical that is ferromagnetically coupled to the unpaired electron of Cu(II). Spectroscopic characterization and theoretical calculations provide a description of the electronic structure of the oxidized complexes. The third chapter looks at a Co(III) complex of 3, which is electron-rich and undergoes redox processes at low potentials. The optical absorption behaviour of the oxidized products is similar to that of the free ligand, suggesting ligand-based oxidation.
As a whole, this thesis describes the effect of strongly electron-donating ligand substituents on the redox and electronic properties of a metal complex. The design leads to an easy strategy by which to tune the electronic structure of a complex by controlling the redox properties of its ligand.

Divisions:Concordia University > Faculty of Arts and Science > Chemistry and Biochemistry
Item Type:Thesis (Masters)
Authors:de Bellefeuille, David
Institution:Concordia University
Degree Name:M. Sc.
Program:Chemistry
Date:18 March 2014
Thesis Supervisor(s):Ottenwaelder, Xavier
ID Code:978499
Deposited By: DAVID DE BELLEFEUILLE
Deposited On:30 Jun 2014 20:18
Last Modified:18 Mar 2018 05:38
All items in Spectrum are protected by copyright, with all rights reserved. The use of items is governed by Spectrum's terms of access.

Repository Staff Only: item control page

Downloads per month over past year

Research related to the current document (at the CORE website)
- Research related to the current document (at the CORE website)
Back to top Back to top